Two step compressor unit and compressor system having the same

ABSTRACT

A compressor unit having a triple trochoidal rotor, which includes a first rotor, a second rotor, a third rotor, a casing, second and first suction ports, and second and first discharge ports; and a driving unit that rotates the three rotors such that external working fluid is sucked into the suction port and the working fluid sucked into the suction port is discharged to the discharge port in a state of being compressed.

RELATED APPLICATIONS

This application is a Continuation-In-Part of U.S. application Ser. No. 13/414,253, filed Mar. 7, 2012, which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Exemplary embodiments of the present invention relate to a compressor unit including a gear rotor, which is constructed as a triple trochoidal rotor such that working fluid can be compressed in a two-stage compression manner to enable the working fluid to be supplied at high pressure, and the volume of working fluid sucked and discharged can be increased to provide a high-speed, high-pressure compression capability, and a compressor system using the same.

2. Background of the Related Art

A compressor unit having a trochoidal rotor includes two gear rotors that are rotated in a state of being engaged with each other to cause working fluid to pass through therebetween to compress the working fluid, and a casing that accommodates the gear rotors therein. The trochoidal rotor is a rotor or gear rotor having trochoidal gear teeth formed on the inner and outer peripheral surfaces thereof.

The above conventional compressor unit includes: a first rotor having a plurality of outwardly extending trochoidal gear teeth formed on the outer peripheral surface thereof; a second rotor that accommodates the first rotor at an eccentric position relative to rotary center axis thereof therein and has a plurality of inwardly extending trochoidal gear teeth formed on the inner peripheral surface thereof in such a manner that the inwardly extending trochoidal gear teeth of the second rotor are in line contact with the outwardly extending trochoidal gear teeth of the first rotor while being engaged with the trochoidal gear teeth of the first rotor; and a casing that sealing accommodates the first and second rotors therein.

The conventional compressor unit as constructed above has a basic operation mechanism in which fluid is sucked and compressed, and is discharged depending on a change in the volume between the first rotor and the second rotor. This compressor unit is relatively simple in structure and can be made small-scale, and thus has been used as a fluid pump over the past few decades.

However, such a conventional compressor unit has a limitation in that it employs only two rotors. That is, although a torque of the first rotor is increased, the working fluid is discharged each time when the first rotor is rotated by one turn, and thus the pressure of the discharged working fluid is not high above a given level. Therefore, the use of the compressor unit is limited at a place where more than a given head is required. In addition, a discharge speed of the fluid is limited, and thus high-speed pumping capability is not provided.

Therefore, there is an urgent need for an improved compressor unit.

SUMMARY OF THE INVENTION

Accordingly, an embodiment of the present invention has been made in order to solve the above-mentioned problems occurring in the prior art, and it is an aspect of the present invention to provide a compressor unit including a gear rotor, which is constructed as a triple trochoidal rotor such that the working fluid can be compressed in a two-stage compression manner to enable the working fluid to be supplied at high pressure, and a compressor system using the same.

Another aspect of the present invention is to provide a compressor unit including a gear rotor, which is constructed as a triple trochoidal rotor such that the volume of working fluid sucked and discharged can be increased to provide a high-speed, high-pressure compression capability, and a compressor system using the same.

In accordance with an aspect of the present invention, a compressor unit may be provided. The compressor unit may include a first rotor having a plurality of outwardly extending trochoidal gear teeth formed on the outer peripheral surface thereof and a stationary shaft securely fixed to a rotary center thereof; a second rotor configured to eccentrically accommodate the first rotor therein, the second rotor having a plurality of inwardly extending trochoidal gear teeth formed on the inner peripheral surface thereof in such a manner that the inwardly extending trochoidal gear teeth of the second rotor are in line contact with the outwardly extending trochoidal gear teeth of the first rotor while being engaged with the trochoidal gear teeth of the first rotor, and a plurality of outwardly extending trochoidal gear teeth formed on the outer peripheral surface thereof, wherein the number of the inwardly extending trochoidal gear teeth of the second rotor is larger than that of the outwardly extending trochoidal gear teeth of the first rotor and the number of the outwardly extending trochoidal gear teeth of the second rotor is equal to that of the inwardly extending trochoidal gear teeth of the second rotor; a third rotor configured to eccentrically accommodate the second rotor therein, and having a plurality of inwardly extending trochoidal gear teeth formed on the inner peripheral surface thereof in such a manner that the inwardly extending trochoidal gear teeth of the third rotor are in line contact with the outwardly extending trochoidal gear teeth of the second rotor while being engaged with the outwardly extending trochoidal gear teeth of the second rotor, where the number of the inwardly extending trochoidal gear teeth of the third rotor is larger than that of the outwardly extending trochoidal gear teeth of the second rotor; a casing configured to sealingly accommodate the first, second and third rotors in such a manner as to be disposed independently of the stationary shaft of the first rotor, and rotatably support the driving shaft of the third rotor in a state in which the driving shaft extends protrudingly to the outside; a second suction port disposed at a side of the driving shaft so as to fluidically connect the inside and the outside of the casing, and position at a portion in which the space between the outwardly extending trochoidal gear teeth of the first rotor and the inwardly extending trochoidal gear teeth of the second rotor are widened maximally when the first, second and third rotors are rotated, and a first suction port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the second rotor and the inwardly extending trochoidal gear teeth of the third rotor is widened maximally; and a second discharge port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the first rotor and the inwardly extending trochoidal gear teeth of the second rotor are narrowed when the first, second and third rotors are rotated, and a first discharge port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the second rotor and the inwardly extending trochoidal gear teeth of the third rotor is narrowed.

In accordance with an aspect of the present invention, a compressor system may be provided. The compressor system may include a compressor unit including a triple trochoidal rotor, the compressor unit including: a first rotor having a plurality of outwardly extending trochoidal gear teeth formed on the outer peripheral surface thereof and a stationary shaft securely fixed to a rotary center thereof; a second rotor configured to eccentrically accommodate the first rotor therein, the second rotor having a plurality of inwardly extending trochoidal gear teeth formed on the inner peripheral surface thereof in such a manner that the inwardly extending trochoidal gear teeth of the second rotor are in line contact with the outwardly extending trochoidal gear teeth of the first rotor while being engaged with the trochoidal gear teeth of the first rotor, and a plurality of outwardly extending trochoidal gear teeth formed on the outer peripheral surface thereof, wherein the number of the inwardly extending trochoidal gear teeth of the second rotor is larger than that of the outwardly extending trochoidal gear teeth of the first rotor and the number of the outwardly extending trochoidal gear teeth of the second rotor is equal to that of the inwardly extending trochoidal gear teeth of the second rotor; a third rotor configured to eccentrically accommodate the second rotor therein, and having a plurality of inwardly extending trochoidal gear teeth formed on the inner peripheral surface thereof in such a manner that the inwardly extending trochoidal gear teeth of the third rotor are in line contact with the outwardly extending trochoidal gear teeth of the second rotor while being engaged with the outwardly extending trochoidal gear teeth of the second rotor, where the number of the inwardly extending trochoidal gear teeth of the third rotor is larger than that of the outwardly extending trochoidal gear teeth of the second rotor; a casing configured to sealingly accommodate the first, second and third rotors in such a manner as to be disposed independently of the stationary shaft of the first rotor, and rotatably support the driving shaft of the third rotor in a state in which the driving shaft extends protrudingly to the outside; a second suction port disposed at a side of the driving shaft so as to fluidically connect the inside and the outside of the casing, and position at a portion in which the space between the outwardly extending trochoidal gear teeth of the first rotor and the inwardly extending trochoidal gear teeth of the second rotor are widened maximally when the first, second and third rotors are rotated, and a first suction port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the second rotor and the inwardly extending trochoidal gear teeth of the third rotor is widened maximally; and a second discharge port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the first rotor and the inwardly extending trochoidal gear teeth of the second rotor are narrowed when the first, second and third rotors are rotated, and a first discharge port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the second rotor and the inwardly extending trochoidal gear teeth of the third rotor is narrowed; and a driving unit connected to the driving shaft, and configured to apply a torque to the driving shaft to rotate the first, second and third rotors such that external working fluid is sucked into the suction port and the working fluid sucked into the suction port is discharged to the discharge port in a state of being compressed.

In an embodiment of the present invention, first discharge port and the second suction port may be fluidically connected to the connection pipe or the inside of the compressor front cover such that the working fluid primarily compressed between the second rotor and the third rotor after being sucked into the first suction port and then primarily discharged through the first discharge port is induced to the second suction port to cause the working fluid to be secondarily compressed between the first rotor and the second rotor, and the primarily discharged fluid is cooled and then is sucked into the second suction port to lower the temperature of the fluid discharged to the second discharge port.

In an embodiment of the present invention, the compressor unit may further include: a suction resistance preventing slot formed in a compressor cover that fixes a central rotary shaft of the first rotor to an external cover upon the rotation of the first, second and the third rotors, in such a manner as to extend from the first and second suction ports; a residue compressed gas rotation resistance preventing slot formed in the compressor cover in such a manner as to extend from the first and second discharge ports; and a compression ratio adjustment slot formed in the compressor cover in such a manner as to extend from the first and second discharge ports.

In an embodiment of the present invention, the compressor unit including a triple trochoidal rotor may be also applied to two-stage expanding turbines, two-stage fluid pumps, vacuum pumps, companders (combined compressors and expanders), and expander pumps (external expanders and internal pumps), besides industrial compressors.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the present invention will be apparent from the following detailed description of embodiments of the invention in conjunction with the accompanying drawings, in which:

FIG. 1 is a view illustrating a two-stage compressor unit including a gear rotor in accordance with an embodiment of the present invention;

FIG. 2 is a view illustrating the construction of a front cover of the compressor unit shown in FIG. 1;

FIG. 3 is a view illustrating the construction of a rotor of the compressor shown in FIG. 1;

FIG. 4 is a view illustrating a side of the compressor shown in FIG. 1;

FIG. 5 is a block diagram illustrating the construction of a compressor system including a gear rotor accordance with an embodiment of the present invention;

FIG. 6 shows a compression mechanism of the compressor system shown in FIG. 5; and

FIG. 7 shows another embodiment of a compression mechanism of the compressor system shown in FIG. 5.

FIG. 8 is a view illustrating an oil feeding path of a third rotor illustrated in FIG. 1.

FIG. 9 is a view illustrating an oil feeding path of a second rotor illustrated in FIG. 1.

FIG. 10 is a view illustrating an oil feeding path of a first rotor illustrated in FIG. 1.

DETAILED DESCRIPTION

Reference will be now made in detail to embodiments of the present invention with reference to the attached drawings. In the following description, the detailed description on known function and constructions unnecessarily obscuring the subject matter of the present invention will be avoided hereinafter. Also, the terms used herein are defined in consideration of the function of the present invention, which may vary according to an intention of a user or an operator or according to custom. Thus, definition of such terms should be made based on content throughout the specification disclosing a compressor unit including a gear rotor and a compressor system using the same according to the present invention.

FIG. 1 is a view illustrating a compressor unit including a gear rotor in accordance with an embodiment of the present invention, FIG. 2 is a view illustrating the construction of a front cover of the compressor unit shown in FIG. 1, FIG. 3 is a view illustrating the construction of a rotor of the compressor shown in FIG. 1, FIG. 4 is a view illustrating a side of the compressor shown in FIG. 1, and FIG. 5 is a block diagram illustrating the construction of a compressor system including a gear rotor accordance with an embodiment of the present invention.

In FIG. 2 of the drawings, reference number “11” designates an oil injection port for oil supplied to gear teeth side, reference number “24-1” designates an oil injection port for oil supplied to oil chamber side inside a compressor cover, reference number “25” designates the oil chamber, wherein it is an oil supplying chamber for supplying oil to first, second and third rotors and a central bearing of a stationary shaft. Furthermore, reference number “26” designates an oil feeding path of third rotor oil for supplying the oil to the third rotor side.

In FIG. 4, reference number “34” designates a bearing, reference number “35” designates an oil passageway formed inside a driving shaft 20, and reference number “36” designates an oil passageway formed at the bearing 34 side inside the driving shaft 20.

Referring to FIGS. 1 to 5, a compressor unit 12 according to an embodiment of the present invention includes a trochoidal rotor assembly 18 in which three trochoidal rotors 14, 13 and 15 are engaged with each other, and a casing 17 that sealingly accommodates the assembly 18 therein. The casing 17 is fabricated in a cylindrical shape having a predetermined diameter.

The trochoidal rotor assembly 18 includes a first rotor 15, a second rotor 14 that accommodates the first rotor 15 at an eccentric position therein, and a third rotor 13 that accommodates the second rotor 14 at an eccentric position therein.

Further, similar to a typical trochoidal gear pump, the first rotor 15 and the second rotor 14 are engaged with each other, and simultaneously are in line contact with each other. The third rotor 13 is in line contact with the second rotor while being engaged with the second rotor 14. A stationary shaft is securely fixed to a front cover 19 of the compressor unit by a shaft center 16 at a rotary center axis of the first rotor 15.

In addition, a driving shaft 20 extends in a longitudinal direction in a state of being joined to the third rotor 13 such that the driving shaft 20 is protruded to the outside of the casing 17 by a predetermined length while passing through the casing 17 as shown in FIG. 4. The driving shaft 20 is axially rotated by receiving a torque from an external driving unit 21 such that the first, second and third rotors 15, 14, and 13 are rotated together with the driving shaft 20. Thus, it can be seen from FIG. 5 that the driving shaft 20 of the compressor unit 12 is connected to the driving unit 21. The driving unit 21 is a motor or engine that can provide a torque.

In addition, first and second suction ports 1 and 3 are all opened, and a second discharge port 8 is fluidically connected to an oil separator and oil tank 22. Fluid discharged upon the rotation of the first, second and third rotors increases the internal pressure of the oil separator and oil tank 22 through a second discharge port 8 to cause lubricant oil contained in the oil separator and oil tank 22 to be supplied the third and second rotors 13 and 14 through a lubricant oil injection port 11. The oil separator and oil tank 22 is connected to the compressed air storage tank 23. The compressed air storage tank 23 serves to temporarily store the compressed gas discharged from the compressor unit 12, and may not be installed according to embodiments.

In the case where the compressed air storage tank 23 is not installed in a compressor system according to the present invention, the oil separator and oil tank 22 is directly connected to a demand place requiring compressed air by a connection pipe 24 for discharge of air. In addition, when high-pressure air is not required, the connection between the second suction port 3 and the first discharge port 5 is interrupted, and the first suction port 1 and the second suction port 3 are fluidically connected to each other and the second discharge port 8 and the first discharge port 5 are fluidically connected to each other such that low-pressure air is used in a one-stage compression manner.

Further, as described above, since the first and second suction ports 3 and 1 are fluidically connected to each other, the volume of air sucked is increased as much such that low-pressure compressed air can be discharged in a large amount at a time. The compressor unit as constructed above is suitable for a demand place requiring a large quantity of low-pressure and high-pressure compressed air for a limited time period. Further, as described above, low-pressure and high-pressure compressed air can be simply produced through the fluidical connections between the first and second suction ports 3 and 1, and between the first and second discharge ports 5 and 8. The detailed driving mechanism of the first, second and third rotors included in the compressor unit 12 will be described later with reference to FIG. 6.

Referring to FIG. 5, it can be seen that the first discharge port 5 is fluidically connected to the second suction port 3 through the connection pipe 24. Moreover, the second discharge port 8 is connected to the oil separator and oil tank 22, and is connected to the compressed air storage tank 23 through the connection pipe 24.

In the above construction, when the driving shaft 20 is axially rotated by the driving unit 21, external air is sucked into the first suction port 1. The air sucked into the first suction port 1 flows along a first suction port slot 2 penetratingly formed in the front cover 19 of the compressor unit to cause the sucked air to be supplied in a maximum amount supplied between the third rotor 13 and the second rotor 14 without any fluid resistance as shown in FIGS. 2 to 4. The first suction port slot 2 of the front cover 19 is used to prevent resistance of the sucked air. The sucked air is primarily compressed while being circulated in the inside of the casing 17 between the second rotor 14 and the third rotor 13, and then is discharged through the first discharge port 5. In this case, the compressed gas first reaches a compression ratio adjustment slot 6 before reaching he first discharge port 5. The aim of the compression ratio adjustment slot 6 is to adjust the compression ratio of the compressed air, the amount of air discharged primarily, and the amount of air sucked secondarily. The length of the compression ratio adjustment slot 6 varies depending on the adjustment amount of the compressed air. A compressed air resistance preventing slot 7 is penetratingly formed in the front cover 19 of the compressor unit so as to prevent compression of air remained after being discharged through the first discharge port 5 as shown in FIG. 2. The aim of the compressed air resistance preventing slot 7 is to smoothly discharge lubricant oil supplied while receiving rotation resistance of the rotors by compression of the compressed air that is not totally discharged from the first discharge port 5.

The compressed air discharged through the first discharge port 5 is moved to the second suction port 3 through the connection pipe 24, and is sucked between the second rotor and the first rotor along a second suction port slot 4 penetratingly formed therein without any fluid suction resistance as shown in FIGS. 2 and 4. The aim of the second suction port slot 4 is to prevent suction resistance of the sucked compressed air. The sucked compressed air is again compressed between the first rotor 15 and the second rotor 14, and reaches the compression ratio adjustment slot 9. The aim of the compression ratio adjustment slot 9 is to adjust the compression ratio.

Then, the compressed air is discharged to the second discharge port 8 via the compression ratio adjustment slot 9, and the compressed air and oil that is not discharged but remained in the compression ratio adjustment slot 9 is discharged through a compressed air resistance preventing slot 10 for the second discharge port. The aim of the compressed air resistance preventing slot 10 for second discharge port is to remove rotation resistance of the rotors by compression of the compressed air and oil that is remained and to smoothly rotate the rotors. When the compressed air is discharged to the outside of the casing 17 through the second discharge port 8 and is supplied to the oil separator and oil tank 22, the internal pressure of the oil separator and oil tank 22 is increased to cause the lubricant oil contained in the oil separator and oil tank 22 to be supplied between the third rotor 13 and the second rotor 14 through the oil injection port 11 of the compressor front cover 19. In this case, since the third rotor 13 and the second rotor 14 are first opened, the inside of the oil separator and oil tank 22 become a vacuum state to cause the lubricant oil to be smoothly supplied between the third rotor and the second rotor due to the internal pressure of the oil separator and oil tank 22.

The compressed air collected in the oil separator and oil tank 22 is moved to and is temporarily stored in the compressed air storage tank 23 through the connection pipe 24. In the case where the compressed air needs not to be stored in the compressed air storage tank 23, it may not be installed.

FIG. 6 shows a compression mechanism of the compressor system shown in FIG. 5.

The operation mechanism of the compressor unit shown in FIG. 5 is as follows. Working fluid is simultaneously sucked into two suction ports and is simultaneously discharged to two discharge ports.

As shown in FIG. 6, when the driving shaft 20 is rotated, the trochoidal rotor assembly 18 is rotated at its entirety together with the driving shaft 20. Then, the spaces defined between the first rotor 15 and the second rotor 14 and between the second rotor 14 and the third rotor 13, where the second and first suction ports 3 and 1 are positioned, are widened. Thus, the pressure between the first, second and third rotors 15, 14 and 13 is decreased to cause external working fluid to be introduced into the casing through the first and second suction ports 1 and 3 as shown in FIG. 6 a.

In this state, when the driving shaft 20 continues to be rotated, the working fluid is compressed while being rotated in a state of being caught between the first, second and the third rotors 15, 14 and 13, and then approaches the first and second discharge ports 5 and 8 as shown in (b) of FIG. 6.

As shown in (c) of FIG. 6, when the working fluid being moved in a state of being caught between the first, second and the third rotors 15, 14 and 13 finally reaches the first and second discharge ports 5 and 8, it is simultaneously discharged to the outside through the two discharge ports 5 and 8 such that the working fluid is supplied to a demand place or is temporarily stored in the compressed air storage tank 23.

FIG. 7 shows another embodiment of a compression mechanism of the compressor unit shown in FIG. 5.

The operation mechanism of the compressor unit shown in FIG. 5 is basically, as follows. First, working fluid is allowed to be sucked into the first suction port 1 so as to be primarily compressed, and then is secondarily compressed in the casing 17 via the first discharge port 5 and the second suction port 3. Then, the working fluid is finally discharged to the second discharge ports 8.

As shown in (a) of FIG. 7, when the driving shaft 20 is rotated by the driving unit 21 (see FIG. 5), external working fluid is introduced into the casing 17 through the first suction port 1. Then, the working fluid introduced into the casing 17 is compressed while being moved to the first discharge port 5 in a state of being caught between second rotor 14 and the third rotor 13 (see (b) and (c) of FIG. 7).

As shown in (c) of FIG. 7, the working fluid that has reached the first discharge port 5 escapes to the outside through the first discharge port 5 and is moved to the second suction port 3 through the connection pipe 24.

Then, the working fluid moved to the second suction port 3 is sucked between the first rotor 15 and the second rotor 14 as shown in (d) of FIG. 7. Thereafter, as shown in (e) of FIG. 7, the sucked working fluid is again compressed between the first rotor 15 and the second rotor 14, and then is moved to the second discharge ports 8 so as to be discharged to the outside (see (f) of FIG. 7).

Meanwhile, FIG. 8 is a view illustrating an oil feeding path of a third rotor illustrated in FIG. 1, FIG. 9 is a view illustrating an oil feeding path of a second rotor illustrated in FIG. 1, and FIG. 10 is a view illustrating an oil feeding path of a first rotor illustrated in FIG. 1.

Referring to the drawings, description will be given of a lubrication system in a compressor unit according to an example of the present invention.

Oil is supplied from the external oil separator and oil tank (“22” in FIG. 5) to the oil injection port (“11” in FIG. 2) and oil feeding injection port (“24” in FIG. 2) disposed in the outer front cover (“19” in FIG. 4) of the compressor, and the oil flowed into the oil feeding injection port (“24” in FIG. 2) fills the oil chamber (“25” in FIG. 2) and oil feeding path (“26” in FIG. 2) positioned at inner side of the front cover and is supplied to a circular oil feeding path 27 formed in the third rotor 13 illustrated in FIG. 9, thereby lubricating between the third rotor 13 and the front outer cover 19.

Furthermore, referring to FIG. 10 illustrating an oil feeding path of the second rotor 14, the oil is supplied to the second rotor 14, first rotor 15 and stationary shaft bearing through the oil chamber (“25” in FIG. 2) and oil feeding path (“26” in FIG. 2) positioned at inner side of the front cover, and the oil is supplied to the teeth of the gear through the oil passageway (“30” in FIG. 10) of the second rotor 14 to lubricate the teeth, and the oil is supplied to the second rotor 14 contacting with the driving shaft opposite the gear through an hole of an oil feeding port (“28” in FIG. 10) to lubricate the second rotor.

In FIG. 9, reference number “29” designates a lubrication passageway of the rotor gear teeth in the second rotor 14.

Furthermore, referring to FIG. 10 illustrating an oil feeding path of the first rotor 15, the oil is supplied to an oil feeding passageway 33 through the oil chamber (“25” in FIG. 2) positioned at inner side of the front cover to lubricate side surfaces of the gear and the oil is supplied to the teeth of the gear to lubricate between the front cover and the gear. At this time, the oil is supplied through a hole of the oil passageway 31 to the oil passageway 31, lubrication passageway 32 and oil feeding passageway 33 positioned in parts where the opposite driving shaft and side surface of the gear contact with each other to lubricate the driving shaft and contact surfaces of the gear.

In FIG. 10, reference number “32” designates a lubrication passageway of the teeth of the first rotor 15.

Meanwhile, the oil discharged from the oil separator and oil tank 22 is supplied to the bearing 34 installed on the shaft through the oil passageway 35 illustrated in FIG. 4 and the oil passageway 36 leading to the bearing 34 inside the shaft, and finally is supplied to the bearing 34 of the stationary shaft passing through the center of the first rotor 15 of the rotor assembly 18 and installed in the front outer cover 19.

As described above, the two-stage compressor unit according to an embodiment of the present invention can increase the discharge speed of the working fluid or can compress the working fluid in a two-stage compression manner to implement a high-speed, high-pressure compression capability.

The two-stage compressor unit including a triple trochoidal rotor and the compressor system using the same as described above can be applied to industrial compressors, two-stage expanding turbines, two-stage fluid pumps, vacuum pumps, companders (combined compressors and expanders), and expander pumps (external expanders and internal pumps), which can implement a high-speed, high-pressure compression capability.

As described above, the compressor unit including a gear rotor and the compressor system using the same in accordance with the exemplary embodiments of the present invention has the following advantageous effects.

First, an embodiment of the present invention is constructed as a triple trochoidal rotor such that working fluid can be compressed in a two-stage compression manner to enable the working fluid to be supplied at high pressure.

Second, an embodiment of the present invention is constructed as a triple trochoidal rotor such that the volume of working fluid sucked and discharged can be increased to provide a high-speed, high-pressure compression capability.

While the present invention has been described in connection with the exemplary embodiments illustrated in the drawings, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the meaning of the invention or limit the scope of the invention disclosed in the claims. Also, it is to be understood that various equivalent modifications and variations of the embodiments can be made by a person having an ordinary skill in the art without departing from the spirit and scope of the present invention. Therefore, various embodiments of the present invention are merely for reference in defining the scope of the invention, and the true technical scope of the present invention should be defined by the technical spirit of the appended claims and their equivalents. 

What is claimed is:
 1. A two-stage compressor unit comprising: a first rotor having a plurality of outwardly extending trochoidal gear teeth formed on an outer peripheral surface thereof and a stationary shaft securely fixed to a rotary center thereof; a second rotor configured to eccentrically accommodate the first rotor therein, the second rotor having a plurality of inwardly extending trochoidal gear teeth formed on an inner peripheral surface thereof in such a manner that the inwardly extending trochoidal gear teeth of the second rotor are in line contact with the outwardly extending trochoidal gear teeth of the first rotor while being engaged with the trochoidal gear teeth of the first rotor, and a plurality of outwardly extending trochoidal gear teeth formed on an outer peripheral surface thereof, wherein a number of the inwardly extending trochoidal gear teeth of the second rotor is larger than that of the outwardly extending trochoidal gear teeth of the first rotor and a number of the outwardly extending trochoidal gear teeth of the second rotor is equal to that of the inwardly extending trochoidal gear teeth of the second rotor; a third rotor configured to eccentrically accommodate the second rotor therein, and having a plurality of inwardly extending trochoidal gear teeth formed on an inner peripheral surface thereof in such a manner that the inwardly extending trochoidal gear teeth of the third rotor are in line contact with the outwardly extending trochoidal gear teeth of the second rotor while being engaged with the outwardly extending trochoidal gear teeth of the second rotor, where a number of the inwardly extending trochoidal gear teeth of the third rotor is larger than that of the outwardly extending trochoidal gear teeth of the second rotor; a casing configured to sealingly accommodate the first, second and third rotors in such a manner as to be disposed independently of the stationary shaft of the first rotor, and rotatably support the driving shaft of the third rotor in a state in which the driving shaft extends protrudingly to the outside; a second suction port disposed at a side of the driving shaft so as to fluidically connect an inside and an outside of the casing, and position at a portion in which the space between the outwardly extending trochoidal gear teeth of the first rotor and the inwardly extending trochoidal gear teeth of the second rotor are widened maximally when the first, second and third rotors are rotated, and a first suction port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the second rotor and the inwardly extending trochoidal gear teeth of the third rotor is widened maximally; and a second discharge port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the first rotor and the inwardly extending trochoidal gear teeth of the second rotor are narrowed when the first, second and third rotors are rotated, and a first discharge port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the second rotor and the inwardly extending trochoidal gear teeth of the third rotor is narrowed.
 2. The two-stage compressor unit according to claim 1, further comprising: a suction resistance preventing slot formed in a compressor cover that fixes a central rotary shaft of the first rotor to an external cover upon the rotation of the first, second and the third rotors, in such a manner as to extend from the first and second suction ports; a residue compressed gas rotation resistance preventing slot formed in the compressor cover in such a manner as to extend from the first and second discharge ports; and a compression ratio adjustment slot formed in the compressor cover in such a manner as to extend from the first and second discharge ports.
 3. A compressor system comprising: a two-stage compressor unit including a triple trochoidal rotor, the compressor unit comprising: a first rotor having a plurality of outwardly extending trochoidal gear teeth formed on an outer peripheral surface thereof and a stationary shaft securely fixed to a rotary center thereof; a second rotor configured to eccentrically accommodate the first rotor therein, the second rotor having a plurality of inwardly extending trochoidal gear teeth formed on an inner peripheral surface thereof in such a manner that the inwardly extending trochoidal gear teeth of the second rotor are in line contact with the outwardly extending trochoidal gear teeth of the first rotor while being engaged with the trochoidal gear teeth of the first rotor, and a plurality of outwardly extending trochoidal gear teeth formed on an outer peripheral surface thereof, wherein a number of the inwardly extending trochoidal gear teeth of the second rotor is larger than that of the outwardly extending trochoidal gear teeth of the first rotor and a number of the outwardly extending trochoidal gear teeth of the second rotor is equal to that of the inwardly extending trochoidal gear teeth of the second rotor; a third rotor configured to eccentrically accommodate the second rotor therein, and having a plurality of inwardly extending trochoidal gear teeth formed on an inner peripheral surface thereof in such a manner that the inwardly extending trochoidal gear teeth of the third rotor are in line contact with the outwardly extending trochoidal gear teeth of the second rotor while being engaged with the outwardly extending trochoidal gear teeth of the second rotor, where a number of the inwardly extending trochoidal gear teeth of the third rotor is larger than that of the outwardly extending trochoidal gear teeth of the second rotor; a casing configured to sealingly accommodate the first, second and third rotors in such a manner as to be disposed independently of the stationary shaft of the first rotor, and rotatably support the driving shaft of the third rotor in a state in which the driving shaft extends protrudingly to the outside; a second suction port disposed at a side of the driving shaft so as to fluidically connect an inside and an outside of the casing, and position at a portion in which the space between the outwardly extending trochoidal gear teeth of the first rotor and the inwardly extending trochoidal gear teeth of the second rotor are widened maximally when the first, second and third rotors are rotated, and a first suction port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the second rotor and the inwardly extending trochoidal gear teeth of the third rotor is widened maximally; and a second discharge port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the first rotor and the inwardly extending trochoidal gear teeth of the second rotor are narrowed when the first, second and third rotors are rotated, and a first discharge port positioned at a portion in which the space between the outwardly extending trochoidal gear teeth of the second rotor and the inwardly extending trochoidal gear teeth of the third rotor is narrowed; and a driving unit connected to the driving shaft, and configured to apply a torque to the driving shaft to rotate the first, second and third rotors such that external working fluid is sucked into the suction port and the working fluid sucked into the suction port is discharged to the discharge port in a state of being compressed.
 4. The compressor system according to claim 3, wherein first discharge port and the second suction port are fluidically connected to the connection pipe or the inside of the compressor front cover such that the working fluid primarily compressed between the second rotor and the third rotor after being sucked into the first suction port and then primarily discharged through the first discharge port is induced to the second suction port to cause the working fluid to be secondarily compressed between the first rotor and the second rotor, and the primarily discharged fluid is cooled and then is sucked into the second suction port to lower the temperature of the fluid discharged to the second discharge port.
 5. The compressor system according to claim 1, wherein the compressor unit further comprises: a suction resistance preventing slot formed in a compressor cover that fixes a central rotary shaft of the first rotor to an external cover upon the rotation of the first, second and the third rotors, in such a manner as to extend from the first and second suction ports; a residue compressed gas rotation resistance preventing slot formed in the compressor cover in such a manner as to extend from the first and second discharge ports; and a compression ratio adjustment slot formed in the compressor cover in such a manner as to extend from the first and second discharge ports.
 6. The two-stage compressor unit according to claim 1, wherein the two-stage compressor unit including a triple trochoidal rotor is applied to any one of two-stage expanding turbines, two-stage fluid pumps, vacuum pumps, companders (combined compressors and expanders), and expanding turbine pumps (external expanding turbine and internal pumps), besides industrial compressors.
 7. The compressor system according to claim 3, further comprising a lubrication system wherein an oil chamber and an oil feeding path are arranged at inner side of the front cover of the compressor to supply the oil to an oil feeding path of the third rotor, and wherein an oil chamber is arranged at parts where the first, second and third rotors contact to supply the oil to the first, second and third rotors and bearings of central stationary shaft, and wherein an oil circulation groove is formed in each rotor to lubricate contact surface of the front cover of the compressor and each rotor.
 8. The compressor system according to claim 3, further comprising a lubrication system wherein oil is supplied through an oil passageway formed inside the driving shaft and oil is supplied to a bearing installed on the driving shaft through an oil passageway leading to the bearing inside the driving shaft, and wherein by supplying oil through an oil passageway formed inside the driving shaft, the oil is supplied to the bearings disposed on the driving shaft and the stationary shaft passing through the center of the first rotor of the rotor assembly and installed in the front outer cover of the compressor.
 9. The compressor system according to claim 3, wherein the two-stage compressor unit including a triple trochoidal rotor is applied to any one of two-stage expanding turbines, two-stage fluid pumps, vacuum pumps, companders (combined compressors and expanders), and expanding turbine pumps (external expanding turbine and internal pumps), besides industrial compressors. 